Egr Total Blanking Plate On C5 2.0 16V 138Bhp (2004-2008)

[picnmix]

I'm having occasional problems (comes and goes at random) with lumpy running on my 2005 C5 facelift model 2.0 HDI 16v 138bhp with 45,000 miles. The symptoms when it occurs, are unstable idle (constantly reving up and down from 500 - 1300rpm), hesitation when accelerating and a lurching feeling when driving - it holds back and then suddenly goes.  No warning lights or dash messages and no errors logged when checked with Lexia.

 

It seemed possible that the EGR was at fault so the simple solution seemed a blanking plate. I chose the type if a small hole in centre as I was concerned that with this engine the management system might notice a totally blanked off EGR.  This has improved things about 50% but its still happens and is very annoying when it does. So I think I'm on to something with it being caused by the EGR valve, with it perhaps sticking and staying open when it should be closed hence the partial restriction with the holed blanking plate helping to reduce the symptoms. I could replace/clean the EGR value but I'm thinking the problem could be back sooner or later.

 

My question is with this engine (2.0 HDI 16v 138bhp) should I just fit a total blanking plate without the hole or would the engine notice and complain with messages and limp home mode?

 

Thanks, Chris.     

[qman3428]

My car has been reporting an erg electrical failure for over 3 years, it has not affected the running and has the same effect as a fully blanked off egr so I have not rushed to fix it. Even the main dealer advise me to ignore it.

[Randombloke]

My question is with this engine (2.0 HDI 16v 138bhp) should I just fit a total blanking plate without the hole or would the engine notice and complain with messages and limp home mode?

 

 

I tried it (cheap, solid plate with no hole) on my 407 (2007) with the same engine and there was no improvement to the running or MPG, but then there were no pre-existing faults. It did not complain or flag up any issues. 

 

By comparison on my previous C5 (2002) with the 136hp 2.2 litre there was a noticeable improvement in throttle pick up and MPG.

[paul.h]

egr valves are not supposed to work until the engine is warmed so another indication of a problem with it would be if the car does not show any symptoms when first started. Also I have read they can result in a lot of smoke from the exhaust when faulty.

 

Did you check if the dpf is regenerating a lot when you used the Lexia since there is a recent post on a C8 with similar problems which may be related to the dpf/a lack of eolys fluid/frequent regenerations as the dpf blocks.

[picnmix]

Umm thanks - I think you are on to something with the DPF.  I beginning to think the problem is sort of regular about every 300 miles I'm guessing suddenly starts and then is fine 10 or 15 minutes later as if it coincides with a DPF regeneration.  

[paul.h]

This is the C8 post on intermittent loss of power with a link to the dpf one http://www.citroen-owners-club.co.uk/citroen/topic/21158-intermittent-loss-of-power/

[picnmix]

Thanks the best lead I have at the moment is from a Peugeot forum (same engine).  This is the quote :

 

"Hi everyone, I am an experienced independant mechanic. I work alot at HDI's. Basically what is happening is that your car is requesting regeneration assistance every say 400 mile or 600 KM, ie you will only experience the problem at these intervals. It will start the regen say 10 - 15 mins after starting car. During regen the car bypasses the intercooler. It does this by closing the top doser valve and opening the bottom valve. Your cars are closing the top valve but not opening the bottom. This chokes the car of air and to prevent stalling opens and closes the top doser. The car will rev up and down from 500 to 1500 rpm on idle and give out bursts of smoke from exhaust. it will also lack power and chug alot until it hits higher revs. The 3 things that can cause this is the bottom doser is broken (ie flaps about loose when hose is removed), the second is a vacuum problem ie leak from pipe etc and the third is a faulty solenoid which is at the bottom left on front of engine, 2 bolted togeather and they are both brown, i think the bottom doser is the back solenoid next block, i cant remember. If you pull vacuum pipe off top doser when the car is idling erratically it should let it idle smooth. It may not be safe to drive with it disconnected incase the dosers close for engine braking? Im not sure. "

[coastline taxis]

diagnostic into live data and take car for a run and that should show you what is wrong when the fault comes on otherwise your just guessing